石灰对酸化黄壤整治烟田土壤酸度的影响及其应用效果

摘要

采用室内培养试验和田间试验相结合的方法，研究土壤酸度对石灰施用量的动态响应规律，以及石灰施用量对烤烟农艺性状及经济性状的影响。结果表明：酸化黄壤在室内培养环境下对石灰的响应可分为3个阶段，即快速变化阶段，土壤pH值急剧升高，持续时间较短；缓慢变化阶段，土壤pH值的变化速度以及持续时间受石灰施用量的影响，石灰施用量低于3.00 t/hm2时该阶段持续时间约60 d，石灰施用量高于4.50 t/hm2时该阶段持续时间为15~30 d；稳定阶段，石灰施用量与土壤pH值间呈显著的非线性正相关关系。田间试验研究表明，土壤pH值随石灰施用量的变化规律基本与室内试验研究结果相吻合。综合石灰施用量对烤烟影响发现，在pH值为5.0左右的酸性黄壤整治烟田中，推荐提前移栽期60 d向烟田垄体中施入1.50 t/hm2的石灰以矫正土壤酸度，促进烤烟生产。%A series of laboratory and field experiments were conducted to study the effects of lime dosage on dynamic response of pH value, agronomic traits and economic traits of flue-cured tobacco in acidified yellow soil in renovated flue-cured tobacco field. The results showed that: the pH changes of acidified yellow soil were roughly divided into three phases according to the response characteristics of soil pH value to lime dosage in different periods during incubation course. The first phase was a rap-id changing stage, showing a sharp increase in soil pH value with relatively short duration. The second phase was a slowly changing stage which the direction of change, rate of change in soil pH value and duration period were affected by lime dosage. When the lime dosage was less than 3. 00 t/hm2 , the duration was about 60 days. When the lime dosage was more than 4. 50 t/hm2 , rate of pH change increased with increasing liming dosage and the duration was risen from 15 days to 30 days. The last phase was a stable stage presenting stable pH value, in which lime dosage and soil pH was significantly positively correlated and fitted to non-linear relationship. The field experiment showed that the trend of pH value varied with the amount of liming, which was basically consistent with results of incubation experiment. Combined with effects of soil pH value and flue-cured tobacco, ap-plying 1. 50 t/hm2 lime into ridges before transplanting period about 60 days was suitable for correcting acidity of yellow soil at the condition of pH value was about 5. 0.